The present invention relates to aircraft pressure probes, in general, and more particularly, to a pressure probe including a pitot tube assembly mounted to a surface of an aircraft by a strut, and a pressure sensor and signal conditioning circuitry integral to the strut for converting the pressure collected by the pitot tube assembly to an electrical pressure signal.
Total pressure and/or static pressure of air surrounding a surface of an aircraft is (are) generally collected by a pitot tube assembly mounted to the aircraft surface for use in calculating air speed and altitude among other parameters. Currently, the pitot tube assembly is mounted to the surface of the aircraft using a metal strut. Because of the extremely low temperatures encountered at the aircraft surface, especially during flight at high altitudes, a heating element is included in the pitot tube assembly for preventing ice from forming on and in the assembly which could adversely affect the pressure collection thereof. Accordingly, heat from the assembly is conducted to the metal strut which could attain temperatures on the order of 300xc2x0 F., for example, at still air conditions.
Most pressure probes of the aforementioned type conduct the pressure collected thereby through pneumatic tubing to a central location on the aircraft, like the cockpit, for example, where an electronic air data processor may be located for converting the pneumatic pressure to an electrical signal and calculating the desired parameter(s) therefrom. Assembling this pneumatic tubing through the aircraft is cumbersome, costly and adds weight to the craft. Maintaining the tubing is also no easy task. Accordingly, it is desirable to eliminate this pneumatic tubing in modem aircraft if at all possible.
Recently, Rosemount Aerospace Inc. d.b.a. BFGoodrich Aerospace Sensors began marketing a aircraft pressure probe under the tradename Smart Probe(trademark) in which a box of electronics is disposed on the aircraft in close proximity to the pressure probe for converting the pneumatic pressure to an electrical signal and calculating the desired parameter(s) therefrom which are then conducted through electrical conductors to drive instruments in the cockpit for use by the pilot. While this solution eliminated the pneumatic tubing as desired, the added electronics for each pressure probe raises the cost thereof rendering these probes affordable to only a select few.
The present invention comprises an aircraft pressure probe which eliminates the pneumatic tubing of the current probes providing for easier and less expensive assembly and maintenance on the aircraft as well as removing weight. Also, as a result of improved manufacturing techniques, the inventive pressure probe may be rendered as affordable as the current pressure probes.
In accordance with one aspect of the present invention, an electric pressure probe for an aircraft comprises: a pitot tube assembly for collecting pneumatically air pressure in the vicinity of said assembly; a strut including one end mountable to a surface of the aircraft, said pitot tube assembly being coupled to another end of said strut for being supported away from said aircraft surface; a pressure sensor integral to said strut and pneumatically coupled to said pitot tube assembly for converting the pneumatic pressure collected thereby to an electrical pressure signal; and circuitry integral to said strut and coupled to said pressure sensor for signal conditioning said electrical pressure signal, said circuitry including at least one output lead for conducting said conditioned electrical signal from said probe.
In accordance with another aspect of the present invention, a method of making an integral electric pressure probe comprises the steps of coupling one end of a housing to a pitot tube assembly; molding a moldable material into the form of a strut including one end for being mounted to a surface of an aircraft; and molding another end of the housing to another end of the strut.